(1) Field of the Invention
The present invention generally relates to a disk apparatus, and more particularly to a disk apparatus having a holder into which a disk cartridge is inserted, the holder being moved to a disk loading position by a movement of a sliding member.
(2) Description of the Related Art
Recently, a magnetic disk apparatus which performs a magnetic recording/reproducing operation by using a disk cartridge in which a flexible magnetic disk is accommodated, has become miniaturized and reduced in thickness. Such a miniaturization results in a decrease in space between parts constituting the magnetic disk apparatus, and thus a more precise machining has been required for each of the parts.
Generally, a conventional magnetic disk apparatus using a disk cartridge comprises a holder into which the disk cartridge is inserted, a slider which moves the holder, and a frame which movably supports the holder and the slider. The slider slides in an eject direction by an ejecting operation so as to move the holder from a disk loaded position to an eject position. The slider is slidably provided above the holder so as to reduce thickness of the magnetic disk apparatus. A cover member is provided above the slider to slidably support the slider. A shield cover is provided above the cover member.
In the above-mentioned conventional magnetic disk apparatus, since the cover member is provided between the slider and the shield cover, the number of parts is increased and the assembly process is complex. Additionally, guide pins must be screwed onto a bottom surface of the cover member. The guide pins support the slider by engaging with corresponding slots formed on the slider. Accordingly, there is a problem in that working efficiency is low for an assembling operation.
In the above-mentioned conventional magnetic disk apparatus, a movement of the slider to the disk loaded position can be achieved by rotation of a latch lever provided in the magnetic disk apparatus. That is, when the disk cartridge is not inserted, the slider is held at an eject position by the latch lever. When the disk cartridge is inserted into the holder and the latch lever is pressed and rotated by an edge of the disk cartridge, engagement of the slider by the latch lever is released. Since the slider is biased by a coil spring in a direction opposite to a direction in which the disk cartridge is ejected, the slider moves horizontally toward a disk loaded position due to the biasing force of the coil spring. Since the holder has pins which slide in respective slanting slots provided on side surfaces of the slider, the holder is moved down when the slider moves horizontally to the disk loaded position by being guided by the slanting slots.
When the holder is at the disk loaded position, an eject button which is provided on a front end of the slider protrudes from a front surface of the magnetic disk apparatus. The disk cartridge is ejected by pressing the eject button. When the eject button is pressed, the slider is moved horizontally and the holder is moved upwardly to the eject position. At this time, an engagement of the latch lever with the slider is released. Since the latch lever is biased in a rotational direction corresponding to the eject direction by a torsion spring, the disk cartridge in the holder is pressed and ejected from the holder. At this time, the latch lever engages with an engaging portion of the slider so as to rotate while pulling the slider. Accordingly, when the rotation of the latch lever is completed, the slider reaches the eject position.
As mentioned above, in the conventional magnetic disk apparatus, since the coil spring which biases the slider and the torsion spring which biases the latch lever is separately provided, the number of parts is increased. Additionally, when the slider is moved by an ejecting operation, an engaging portion of the slider slides on a cam portion of the latch so as to draw the slider to the eject position. That is, the latch lever draws the slider against a spring force generated by the coil spring biasing the slider. Accordingly, when the latch lever rotates in the eject direction, a force exerted on the cam portion of the latch lever is large, resulting in slowing the rotational movement of the latch lever due to a friction force between the engaging portion and the cam portion.
Additionally, as mentioned above, the engaging portion of the slider is strongly pressed onto the cam portion of the latch lever. Accordingly, a surface of the cam portion may be worn after an extended period of use. When a friction force is generated between the cam portion and the engaging portion due to the wearing of the cam portion, the rotational movement of the latch lever is stopped before it reaches an end position. Accordingly, there is a possibility that a reliable eject operation for the disk cartridge is not achieved.
Additionally, in the conventional magnetic disk apparatus, a head arm provided with a magnetic head has a contact portion which contacts to the holder. The contact portion is pressed against the holder by means of a torsion spring. Accordingly, when the holder moves to the disk loaded position or the eject position, the head arm rotates to have the magnetic head contact the magnetic disk in the disk cartridge or to separate the magnetic head from the magnetic disk, respectively.
As mentioned above, the slider is held at the disk loaded position until the disk cartridge is inserted into the holder. When the disk cartridge is inserted into the holder and a front end of the disk cartridge is pressed against the latch lever, the latch lever rotates in a direction to release the engagement of the slider.
Accordingly, the slider moves to the eject position in which the eject button protrudes from the front surface of the magnetic disk apparatus when the disk cartridge is inserted into the holder. When the slider moves to the eject position, the holder moves downwardly to the disk loaded position.
In the above-mentioned magnetic disk apparatus, the holder is merely supported by the pins protruding from the sides of the holder. The pins engages with the slanting slots formed on the slider. Additionally, the strength of a top plate of the holder is decreased due to a decrease in thickness of the magnetic disk apparatus. Accordingly, in a case in which the magnetic disk apparatus is incorporated into a portable apparatus such as a notebook type personal computer, the top plate of the holder may be elastically bent due to a shock applied while the portable apparatus is carried. In such a case, the head arm bearing against the top plate of the holder may rotate. This causes an upper magnetic head provided on the head arm collide with a lower magnetic head, resulting in damage of the upper and lower magnetic heads.
Additionally, while the holder is at the eject position, the top plate of the holder is always pressed downwardly by the contacting portion of the head arm. Thus, the top plate may be permanently bent downwardly after an extended period of use. In such a case, height of the disk cartridge inserted in the holder is decreased, and thereby the front end of the disk cartridge may contact to and damage the lower magnetic head.